Method for representing virtual information in a view of a real environment

ABSTRACT

A method for representing virtual information in a view of a real environment comprises providing a virtual object having a global position and orientation with respect to a geographic global coordinate system, with first pose data on the global position and orientation of the virtual object, in a database of a server, taking an image of a real environment by a mobile device and providing second pose data as to at which position and with which orientation with respect to the geographic global coordinate system the image was taken. The method further includes displaying the image on a display of the mobile device, accessing the virtual object in the database and positioning the virtual object in the image on the basis of the first and second pose data, manipulating the virtual object or adding a further virtual object, and providing the manipulated virtual object with modified first pose data or the further virtual object with third pose data in the database.

This application is a continuation of U.S. patent application Ser. No.13/501,697 filed May 4, 2012, which is a national stage application ofPCT Application No. PCT Application No. PCT/EP2010/065207 filed on Oct.11, 2010, which claims priority to German Application No. 10 2009 049073.6 filed Oct. 12, 2009.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a method for representing virtualinformation in a view of a real environment.

2. Background Information

Augmented Reality (AR) is a technology in which virtual data areoverlaid with reality and which thus facilitates the association of datawith reality. The use of mobile AR systems is already known in the priorart. In the past years, high-performance mobile devices (e.g.smartphones) turned out to be suitable for AR application. These devicesmeanwhile have comparatively large color displays, installed cameras,good processors and additional sensors, such as e.g. orientation sensorsand GPS. In addition thereto, the position of the device can beapproximated via radio networks.

In the past, there were various projects implemented on mobile devicesusing AR. At first, there were used special optical marks forascertaining the position and orientation of the device. As regards AR,which is usable for large areas as well and thus is also referred to aslarge area AR, there have also been published hints for sensiblerepresentation of objects in connection with HMDs (Head MountedDisplays) (S. Feiner, B. MacIntyre, T. Höllerer, and A. Webster. Atouring machine: Prototyping 3d mobile augmented reality systems forexploring the urban environment. In Proceedings of the 1st InternationalSymposium on Wearable Computers, pages 74-81, 1997). In more recenttimes, there are also approaches to utilize GPS and the orientationsensor systems of modern devices.

However, the approaches published so far have the disadvantage that theydo not permit a simple integration of other users in the AR scenes. Inaddition thereto, most systems based on GPS and compass have thedisadvantage that these devices cogently have to be provided and thatthere may be great inaccuracies occurring.

US 2009/0179895 A1 describes a method of blending in three-dimensionalnotes or annotations in an image of a real environment (“street view”).A user, by way of a selection box in the image, selects the location atwhich an annotation is to be blended in. Thereafter, the selection boxis projected on a three-dimensional model in order to determine aposition of the annotation in relation to the image. Furthermore,location data corresponding to the projection on the three-dimensionalmodel are determined and associated with the annotation entered by theuser. The annotation is stored together with the location data in adatabase of a server and can be blended in another image of the realenvironment in accordance with the location data.

The term “tagging” in general and in the following is used to describeenriching of the reality with additional information by a user.Approaches realized so far in connection with tagging include theplacing of objects in map views (e.g. Google Maps), taking photographsof location points and storing these images together with additionalcommentaries as well as creating text messages at specific locationpoints. There is the disadvantage that remote viewers and users can nolonger obtain AR access to interactive scenes in the world. Onlyso-called screenshots (screen images) of the AR scene can be viewed, butno longer be altered.

It is the object of the present invention to indicate a method forrepresenting virtual information in a view of a real environment, whichpermits users to interactively view AR image scenes created by otherusers by means of augmented reality and to guarantee high accuracy anduser friendliness in doing so.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a methodfor representing virtual information in a view of a real environment,comprising the following steps: providing at least one virtual objecthaving a global position and orientation with respect to a geographicglobal coordinate system, together with first pose data permitting aconclusion to be made on the global position and orientation of thevirtual object, in a database of a server, taking at least one image ofa real environment by means of a mobile device and providing second posedata permitting a conclusion to be made as to at which position and withwhich orientation with respect to the geographic global coordinatesystem the image was taken, displaying the image on a display of themobile device, accessing the virtual object in the database of theserver and positioning the virtual object in the image shown on thedisplay on the basis of the first and second pose data, manipulating thevirtual object or adding a further virtual object by correspondingpositioning in the image shown on the display, and providing themanipulated virtual object together with modified first pose data inaccordance with the positioning in the image or the further virtualobject together with third pose data in accordance with the positioningin the image in the database of the server, the modified first pose dataand third pose data each permitting a conclusion to be made on theglobal position and orientation of the manipulated virtual object or thefurther manipulated object. In this regard, the image can be provided onthe server e.g. together with the second pose data.

According to a further object of the invention, there is provided amethod for representing virtual information in a view of a realenvironment, comprising the following steps: providing at least onevirtual object having a global position and orientation with respect toa geographic global coordinate system, together with first pose datapermitting a conclusion to be made on the global position andorientation of the virtual object, in a database of a server, providingat least one view of a real environment by means of data glasses (e.g. aso-called optical see-through data glasses or video see-through dataglasses) together with second pose data permitting a conclusion to bemade as to at which position and with which orientation with respect tothe geographic global coordinate system the data glasses are positioned,accessing the virtual object in the database of the server andpositioning the virtual object in the view on the basis of the first andsecond pose data, manipulating the virtual object or adding a furthervirtual object by corresponding positioning in the view, and providingthe manipulated virtual object together with modified first pose data inaccordance with the positioning in the view or of the further virtualobject together with third pose data in accordance with the positioningin the view in the database of the server, the modified first pose dataand third pose data each permitting a conclusion to be made on theglobal position and orientation of the manipulated virtual object or thefurther virtual object.

In an embodiment of the invention, the mobile device or the data glassescomprise, or are connected to, a means for generating the second posedata.

For example, the pose data may include respective three-dimensionalvalues concerning position and orientation. Moreover, an orientation ofthe image of the real environment can be defined independently of theearth's surface.

In accordance with another embodiment of the invention, a storinglocation on the server stores in which image of several images of a realenvironment or in which view of several views of a real environment,which virtual object of several virtual objects has been provided withpose data.

When the position of the mobile device is determined e.g. by means of aGPS sensor (GPS: Global Positioning System), it may happen due to sensorinaccuracy or GPS-immanent inaccuracy that the position of the mobiledevice is determined in relatively inaccurate manner only. This may havethe consequence that blended in virtual objects are positioned in theimage relative to the geographic global coordinate system with acorresponding inaccuracy as well, so that in other images or views withdifferent viewing angles, the virtual objects blended in there are shownin correspondingly displaced manner with respect to reality.

For enhanced accuracy of the representation of virtual objects or theposition of the same in the image of the real environment, an embodimentof the method according to the invention comprises the following steps:providing a reference database with reference views of a realenvironment together with pose data permitting a conclusion to be madeas to at which position and with which orientation with respect to thegeographic global coordinate system the respective reference view wastaken by a camera, comparing at least one real object that is shown inthe image with at least part of a real object that is contained in atleast one of the reference views, and matching of the second pose dataof the image with the pose data of the at least one reference view, andmodifying at least part of the second pose data on the basis of at leastpart of the pose data of the at least one reference view as a result ofsaid matching.

Another embodiment, furthermore, comprises modifying at least part ofthe first pose data of the virtual object positioned in the image as aresult of matching of the second pose data of the image with the posedata of said at least one reference view.

Further developments and embodiments of the invention can be taken fromthe dependent claims.

Aspects and embodiments of the invention will be explained in moredetail hereinafter by way of the figures shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a plan view of a schematic arrangement of a firstexemplary embodiment of a system setup that can be used for performing amethod according to the invention,

FIG. 1B shows a plan view of a schematic arrangement of a secondexemplary embodiment of a system setup that can be used for performing amethod according to the invention,

FIG. 1C shows a schematic view of a possible data structure of anembodiment of a system for performing a method according to theinvention,

FIG. 2 shows a schematic view of an overview of participating coordinatesystems according to an embodiment of the invention,

FIG. 3 shows an exemplary course of a method according to an embodimentof the invention,

FIG. 4 shows an exemplary course of a method according to anotherembodiment of the invention, in particular supplemented by optionalmeasures for improving the image pose,

FIG. 5 shows an exemplary scene of a real environment having virtualobjects placed therein, without pose improvement having been effected,

FIG. 6 shows an exemplary scene of a real environment having virtualobjects placed therein, after pose improvement has been effected,

FIG. 7A shows an exemplary map view of the real world in which a virtualobject has been placed,

FIG. 7B shows an exemplary perspective view of the same scene as in FIG.7A.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows a plan view illustrating a schematic arrangement of afirst exemplary embodiment of a system setup which can be used forperforming a method according to the invention.

In the illustration of FIG. 1A, the user wears, as display device, ahead mounted display system (“Head Mounted Display”, abbreviated to HMD)comprising a display 21 that is part of the system setup 20. At leastparts of the system setup 20 may be regarded as a mobile devicecomprising one or more mutually connected components, as will beexplained in more detail hereinafter. The components can be connected toeach other by wire connections and/or in wireless manner. Furthermore,it is also possible that some of the components, such as e.g. thecomputer 23, are provided as stationary components, i.e. do not movealong with the user. The display 21 e.g. may be generally known dataglasses in the form of so-called optical see-through data glasses(“optical see-through display”, in which the reality can be seen throughthe semi-transparent structure of the data glasses) or in the form ofso-called video see-through data glasses (“video see-through display”,in which the reality is represented on a screen worn in front of thehead of the user), in which virtual information provided by a computer23 can be blended in known manner. The user then sees, in a view 70 ofthe real world within a viewing angle or aperture angle 26, that can beseen through the display 21 or on the display 21, objects of the realenvironment 40 that can be augmented with blended in virtual information10 (such as e.g. so-called point of interest objects, briefly referredto as POI objects, related to the real world). The virtual object 10 isblended such that the user perceives the same in a manner as if it werearranged in an approximate position in the real environment 40. Thisposition of the virtual object 10 can also be stored as global positionwith respect to a geographic global coordinate system, such as acoordinate system of the earth, as will still be explained in moredetain hereinafter. In this manner, the system setup 20 constitutes afirst embodiment of a generally known augmented reality system that canbe used for the method according to the present invention.

The display 21 may have additional sensors 24, such as rotation sensors,GPS sensors or ultrasonic sensors, and a camera 22 for optical trackingand for taking one or more images (so-called “views”) mounted thereon.Display 21 can be semi-transparent or may be fed with images of thereality by a camera image of camera 22. With a semi-transparent display21, calibration between eye 25 of the user and display 21 is necessary.This process, referred to as see-through calibration, is known in theart. The calibration advantageously can determine at the same time thepose of the eye in relation to the camera 22. The camera can be used fortaking or recording views in order to make these accessible to otherusers, as will still be explained in more detail hereinafter. The posein general is understood to be the position and orientation of an objectin relation to a reference coordinate system. For determining the pose,there are various methods documented in the prior art and known to theexpert. Advantageously on display 21 or anywhere on the user's body oralso in computer 23, there may also be installed position sensors, suchas e.g. GPS sensors (GPS: Global Positioning System) for renderingpossible a geographic position determination of the system setup 20(e.g. in accordance with longitude, latitude and altitude) in the realworld 40. Pose determination of any part of the system setup is possiblein principle provided that conclusions can be made on the position andviewing direction of the user.

The illustration of FIG. 1B shows another exemplary system setup 30 thatcan be found often e.g. in modern mobile telephones (so-called“smartphones”). A display device 31 (e.g. in the form of a displayscreen or display), computer 33, sensors 34 and camera 32 constitute asystem unit that is accommodated e.g. in a common housing of a mobiletelephone. At least parts of system setup 30 can be regarded as a mobiledevice comprising one or more of the components mentioned. Thecomponents can be accommodated in a common housing or can be distributed(in part) and can be connected to each other by wire connections and/orin wireless manner.

The view of the real environment 40 is provided by display 31 showing animage 50 of the real environment 40 captured by camera 32 in a viewingangle and with an aperture angle 36. For augmented reality applications,the camera image 50 can be shown on display 31 and augmented withadditional virtual information 10 (such as POI objects related to thereal world) that have a specific position in relation to reality,similarly as described in FIG. 1A. In this manner, the system setup 30constitutes another embodiment of a generally known augmented reality(AR) system.

Calibration similar to that described with respect to FIG. 1A is usedfor determining the pose of virtual objects 10 with respect to camera 32in order to make the same accessible to other users, as will still bedescribed in more detail hereinafter. For pose determination, there arevarious methods documented in the prior art and known to the expert.Advantageously on the mobile device (especially when system setup 30 isin the form of a unit) or at any location on the body of the user oralso in computer 33, there may be attached position sensors, e.g. GPSsensors 34 in order to permit geographic position determination of thesystem setup 30 (e.g. in accordance with longitude and latitude) in thereal world 40. In certain situations, there is no camera necessary forpose determination, e.g. when the pose is determined solely by GPS andorientation sensors. Basically, the pose determination of any part ofthe system setup is suitable, as long as conclusions can be made on theposition and viewing direction of the user.

Basically, the present invention can be used expediently for all formsof AR. For example, it is of no relevance whether the representation isimplemented in the so-called optical see-through mode withsemi-transparent HMD or in the video see-through mode with camera anddisplay screen.

The invention basically can also be used in connection with stereoscopicdisplays, in which the video see-through approach advantageously usestwo cameras each for recording one video stream per eye. In anysituation, the items of virtual information can be calculatedindividually for each eye and can also be stored as pair on the server.

The processing of the different partial steps described hereinafterbasically can be distributed to various computers via a network. Thus, aclient/sever architecture or a more client-based solution is possible.Moreover, the client or the server may also comprise several computingunits, such as several Central Processing units (CPUs) or specializedhardware components, such as generally known Field Programmable GateArrays (FPGAs), Application Specific Integrated Circuits (ASICs),Graphics Processing Units (GPUs) or Digital Signal Processors (DSPs).

For permitting AR to be realized, the pose (position and orientation) ofthe camera in space is necessary. This can be realized in variety ofdifferent ways. It is possible to determine the pose in the real worlde.g. by using merely GPS and an orientation sensor with electroniccompass (as installed e.g. in some modern mobile telephones). However,the uncertainty of the pose then is very high. Thus, it is also possibleto use other methods, such as e.g. optical initialization and trackingor the combination of optical methods with GPS and orientation sensors.Wireless Local Area Network (WLAN) locating can be used as well or RFIDs(markers or chips for “radio frequency identification”) or opticalmarkers can support the locating process. As mentioned hereinbefore, aclient/server-based approach is possible here as well. In particular,the client can request from the server location-specific informationneeded for optical tracking Such information may be e.g. referenceimages of the surrounding environment with pose information and depthinformation. An optional embodiment of the present invention in thisregard renders possible in particular to improve the pose of a view onthe server and to improve, on the basis of this information, the pose ofthe placed virtual objects in the world as well.

In addition thereto, the invention can also be installed, or carriedalong, in vehicles, aircraft or ships, making use of a monitor, HMD or ahead-up display.

Basically, virtual objects, such as e.g. a point of interest (“POI”) canbe set up for a large variety of different forms of information.Examples are given hereinafter: It is possible to represent images ofplaces using GPS information. It is possible to automatically extractinformation from the Internet. For example, this may be company orrestaurant websites with addresses or pages giving ratings. Users candeposit texts, images or 3D objects at specific locations and make thesame available to others. Information pages, such as Wikipedia, can besearched for geo-information, and the pages can be made accessible asPOI. POIs can be generated automatically from the search and browsingbehavior of the users of mobile devices. It is possible to show otherlocations of interest, such as underground transportation or busstations, hospitals, police stations, physicians, real estate ads orfitness clubs.

Such items of information can be deposited by a user in image 50 or inview 70 (cp. FIGS. 1A and 1B) as virtual objects 10 at specificlocations in the real world 40 and made accessible to others with theposition corresponding to the respective location. The other users, inan accessible view or image of the real world, can then e.g. manipulatethis information that is blended in accordance with its position, or canalso add further virtual objects. This will be explained in more detailin the following.

FIG. 1C first of all shows data structures that are employed inaccordance with an embodiment of the invention and will be explainedbriefly hereinafter.

A view is a captured view of the real world, in particular a view (cp.view 70 according to FIG. 1A), an image (cp. image 50 according to FIG.1B) or an image sequence (a film or motion picture). Associated with theview (image 50/view 70) are camera parameters that describe opticalproperties of camera 22, 32 (e.g. with respect to aperture angle, focusdisplacement or image distortion) and are to be associated with image 50or view 70, respectively. Besides, the view also has pose dataassociated therewith that describe the position and orientation of theimage 50 or view 70 in relation to the earth. To this end, a geographicglobal coordinate system is associated with the earth so as to renderpossible geographic global location determination in the real world,e.g. in accordance with longitude and latitude.

A placed model is a virtual object that can be displayed graphically(cp. object 10 according to FIGS. 1A, 1B), which has pose data as well.The placed model can represent e.g. an instance of a model of a modeldatabase, i.e. make reference to the same. Advantageously, it isdeposited by which views 50 or 70 the respective virtual model 10 wasplaced in world 40, if this is so. This may be used to improve the posedata, as will still be explained in more detail hereinafter. A sceneconstitutes a combination of a view 50, 70 with 0 to n placed models 10and optionally contains a creation date. All or part of the datastructure can be linked with meta data in addition. For example, thecreator, the date, the frequency of the images/views, ratings and keywords can be deposited.

In the following aspects of the invention with respect to the embodimentaccording to FIG. 1B will be described in more detail, in which an image50 is taken by a camera 32 and is viewed by the viewer on display 31together with blended in virtual objects 10. The statements in thisregard, however, can easily be transferred by the expert analogously tothe embodiment using HMD according to FIG. 1A as well.

FIG. 2 gives an overview of participating coordinate systems accordingto an embodiment of the invention. On the one hand, an earth coordinatesystem 200 is used (which in this embodiment is represented by thegeographic global coordinate system) that constitutes a connectingelement. The earth's surface is indicated in FIG. 2 with numeral 201.For defining a geographic global coordinate system, such as an earthcoordinate system 200, various standards have been defined that areknown to those skilled in the art (e.g. WGS84; NMA—National Imagery andMapping Agency: Department of Defense World Geodetic System 1984;Technical Report, TR 8350.2, 3rd edition, January 2000). Furthermore, acamera coordinate system provides a connection between displayed virtualobjects 10 and images 50. By way of conversions known to the expert, itis possible to calculate from the poses of camera 32 and image 50 inearth coordinate system 200, the pose P50_(—)10 (“pose model in theimage”) of an object 10 relative to image 50. The global image pose PW50(“pose image in the world”) is calculated e.g. via GPS and/ororientation sensors. From poses PW50 and P50_(—)10, the global pose PW10(“pose model in the world”) of the virtual object 10 can then becalculated.

In analogous manner, it is possible to calculate from the pose of asecond image 60 with another global pose PW60 in the earth coordinatesystem 200 the pose P60_(—)10 (“pose model in image 2”) of the object 10relative to image 60. The global image pose PW60 (“pose image 2 in theworld”) is calculated also e.g. via GPS and/or orientation sensors.

In this way it is possible to place a virtual object 10 in a first image(image 50) and to view the same in a second image (image 60) at aposition on the earth located in the vicinity, but from a differentviewing angle. The object 10 is placed, for example, by a first user inthe first image 50 with pose PW10. When a second user with his mobiledevice then generates a view according to image 60, the virtual object10 placed by the first user is automatically blended in image 60 at thesame global position corresponding to pose PW10, provided that the image60 covers in an aperture angle or viewing angle a portion of the realworld which includes the global position of pose PW10.

In the following, aspects and embodiments of the invention will beexplained in more detail by way of the flowcharts of FIGS. 3 and 4 inconjunction with the other figures.

FIG. 3 shows an exemplary course of a method according to an embodimentof the invention. In a first step 1.0, world-related data are generated.These can be extracted e.g. from the Internet or be generated by a firstuser using a camera (FIG. 1B) or a HMD with camera (FIG. 1A). To thisend, the user in step 1.0 takes a view (image or captured view) withrespect to which position and orientation (pose) in the world areascertained (step 2.0). This can take place, for example, using GPS andcompass. Optionally, information regarding uncertainty of the datagenerated can be recorded in addition.

When the view (image or captured view) is present, the user canadvantageously place a virtual object in the view directly on his mobiledevice (step 3.0). Advantageously, the object is placed and manipulatedin the camera coordinate system. In this case, there is calculated instep 4.0 from the global pose of the view and the pose of the object inthe camera coordinate system, the global pose of the virtual object (orobjects) in the world (e.g. in relation to coordinate system 200). Thiscan take place on a client 1 or on a server 2.

A client is a program on a device that establishes contact with anotherprogram on a server in order to use the services of the same. Theunderlying client-server model allows tasks to be distributed todifferent computers in a computer network. A client does not resolve oneor more specific tasks itself, but has them done by the server orreceives corresponding data from the server offering a service to thiseffect. Basically, most steps of this system can be carried out eitheron the server or the client. With clients with high computing capacity,it is e.g. advantageous to have them perform as many calculations aspossible and to thus relieve the server.

In step 5.0, these items of information from step 4.0 are then stored ina database 3 of the server 2, advantageously as described with respectto FIG. 1C. In step 6.0, the same user or another user on another clientthen takes an image of the real environment on (or views a specific partof the environment by means of a HMD) and then loads data stored in step5.0 with respect to a location of the viewed real environment fromserver 2. Loading and displaying the location-related information usingaugmented reality and a database advantageously equipped with geospatialfunction features is known in the art. The user now sees the previouslystored information from the previously stored or a new viewing angle andis capable of effecting changes (manipulation of existing and/or addingnew virtual information), which in turn are stored on server 2. Here,the user does not have to be present, but can use the previous,advantageously stored view as a window on reality, while sitting in hisoffice, for example, at an Internet-enabled client.

In the example of FIGS. 1 and 2, a user thus provides or generates avirtual object 10 on database 3 of server 2 which has a global positionand orientation with respect to a geographic global coordinate system200, together with the pose data (pose PW10) that allow a conclusion tobe made on the global position and orientation of virtual object 10.This user or another user takes at least one image 50 of a realenvironment 40 by means of a mobile device 30 together with the posedata (pose PW50) permitting a conclusion to be made as to at whichposition and with which orientation with respect to the geographicglobal coordinate system 200 the image 50 was taken. The image 50 isdisplayed on display 31 of the mobile device. Access is made to thevirtual object 10 in database 3 of the server, and the virtual object 10then is positioned in image 50 shown on the display on the basis of thepose data of poses PW10 and PW50. The virtual object 10 can then bemanipulated by corresponding positioning (cp. arrow MP in FIG. 1B) inimage 50 shown on the display (e.g. be displaced), or there may beanother virtual object 11 added by corresponding positioning in theimage 50 shown on the display.

Such a manipulated virtual object 10′ together with the modified posedata (modified pose PW10) according to the positioning in image 50 orsuch a further virtual object 11 together with its pose data accordingto the positioning in image 50 is then stored in database 3 of server 2,with the modified pose data PW10 and the pose data of the new virtualobject 11 each permitting a conclusion to be made on the global positionand orientation of the manipulated object 10′ or the further virtualobject 11 with respect to the coordinate system 200.

It may happen in certain cases that the server cannot be reached andthat storing of the new scene thus is not possible. In this event, it isadvantageously possible that the system reacts and provides forbuffering the information until the server is available again. In oneembodiment, in the event of failure of the network connection to theserver, the data to be stored on the server are buffered on the mobiledevice and transmitted to the server when the network connection isavailable again.

In another embodiment, the user can retrieve a collection of scenes inan area of a real environment (e.g. in his surrounding area or localarea) that are made available to him for selection in a list ordered byproximity, or on a map or using augmented reality.

In another embodiment, the image or the virtual information has uniquelyidentifying characteristics (such as unique names), and an image orvirtual information, which is already present on a client or on themobile device (this may be virtual model data or views), will not bedownloaded any more from the server, but is loaded from a local datastorage.

FIG. 4 shows an exemplary course of a method according to anotherembodiment of the invention, in particular supplemented by optionalmeasures for improving the image pose. The method comprises the steps1.0 to 6.0 of FIG. 3. In addition, in steps 7.0 and 8.0 of FIG. 4, thepose of the view (image or captured view) is improved subsequently, forexample by means of optical methods, and due to the advantageous storingof information as to which virtual information was placed by means ofwhich view, the pose of the information is corrected as well.Alternatively, the pose of the view can be improved immediately aftercreating the view already on client 1 by providing optical trackingreference information for this view, or a view with a similar pose, tothe client 1 from a reference database 4 of server 2. Alternatively, theaccuracy of the view can also be effected before computing the pose ofthe virtual objects placed (step 4.0) and can be stored directly incorrect manner. However, an advantage of the subsequent approach is thatreference data do not already have to be available for all locations andthat a correction thus can also be performed for such views as soon asreference data are available.

Of course, it is also possible to use other views are used as referencedata, especially when many views are available for a location. Thismethod, referred to as bundle adjustment, is known in the art, such asdescribed e.g. in the publication of MANOLOS I. A., LOURAKIS and ANTONISA. ARGYROS A: SBA: A Software Package for Generic Sparse BundleAdjustment. In ACM Transactions on Mathematical Software, Vol. 36, No.1, Article 2, Publication date: March 2009. In this case, the 3Dposition of point correspondences, the pose of the views andadvantageously also the intrinsic camera parameters could be optimized.Thus, the approach according to the invention also offers thepossibility to create an own model of the world in order to use suchdata in general. For example, for masking models to support theperception of depth or for optical tracking in real time.

FIG. 5 shows an exemplary scene of a real environment with virtualobjects placed therein it, without a pose improvement having taken placeso far. FIG. 5 shows a possible situation prior to correction. A virtualobject 10 (e.g. a review of a restaurant) is placed, as seen from amobile device 30, in an image shown on display 31 of the device 30 inrelation to real objects 41, 42 (representing e.g. the building of therestaurant). On the basis of incorrect or inaccurate GPS data, both theimage and the object 10 are stored with incorrect world coordinates in amanner corresponding to the incorrectly or inaccurately determinedcamera pose data P30-2. This leads to an object 10-2 that is stored incorrespondingly incorrect manner. This is no problem in this capturedimage as such. However, the error becomes apparent when the virtualobject 10 is viewed e.g. on a map or in another image.

If the image were generated along with true or accurate camera pose dataP30-1, the virtual object 10 would be displayed at a position in theimage, as shown by the representation of the virtual object 10-1 andwould also be viewed in this manner by the user generating the same. Theincorrectly stored virtual object 10-2, however, is shown in anotherimage as displaced from the true position of the virtual object 10, inaccordance with an extent by which the erroneous camera pose P30-2 isdisplaced from the true camera pose P30-1. The representation of theincorrectly stored virtual object 10-2 in the image of the mobile device30 thus does not correspond to the true positioning by the generatinguser in a previous image.

For improving the accuracy of the representation of virtual objects andtheir position in the image of the real environment, an embodiment ofthe method according to the invention comprises the following steps:there is provided a reference database 4 with reference views of a realenvironment together with pose data that permit a conclusion as to atwhich position and with which orientation with respect to the geographicglobal coordinate system 200 the respective reference view was taken bya camera. Then, at least part of a real object shown in the image iscompared with at least part of a real object contained in at least oneof the reference views, and matching of the pose data of the image withthe pose data of the at least one reference view is effected.Thereafter, at least part of the pose data of the image is modified onthe basis of at least part of the pose data of the respective referenceview as a result of matching.

Moreover, in a further embodiment, at least part of the pose data ofvirtual object positioned in the image is modified as a result ofmatching of the pose data of the image with the pose data of therespective reference view.

FIG. 6 shows an exemplary scene of a real environment similar to that ofFIG. 5 with a virtual object 10-1 placed therein, after pose improvementhas taken place. FIG. 6 shows, on the one hand, the mechanism ofrecognition of image features in the image and, on the other hand, thecorresponding correction of image pose and object pose. In particular,image features 43 (e.g. distinctive features of real objects 41 and 42)are compared with corresponding features of reference images of areference database 4 and matched (known as “matching” of imagefeatures).

Now, the virtual object 10 would also be represented correctly in otherimages (that have a correct pose), or a placement correction could beeffected. The expression placement correction is to point out that theuser, in placing a virtual object in perspective manner, could indeedmisjudge the height of the object placed above the ground. By way of twoimages that may overlap in parts of the recorded reality, it may bepossible to extract a ground level and to relocate the objects placed insuch a way that they are on the ground, but in the image, in which theywere originally placed, seem to remain almost in the same location.

FIG. 7A shows an exemplary map view of the real world in which a virtualobject has been placed, whereas FIG. 7B shows an exemplary perspectiveview of the same scene as in FIG. 7A. FIGS. 7A and 7B serve toillustrate in particular the user-assisted determination of the camerapose. For example, it is useful e.g. when mobile devices are used whichare not equipped with compass, to obtain a rough estimate of the viewingdirection. To this end, the user, as shown in FIG. 7B, can take an image50 in the usual manner and place a virtual object 10 in relation to areal object 41. Thereafter the user may be prompted to again show theposition of a placed object 10 on a map 80 or a virtual view 80 of theworld, as shown in FIG. 7A. On the basis of the connection between GPSposition of the image 50 and the object position of object 10 on map 80,it is then possible to calculate or correct the orientation (heading) ofthe image 50 in the world. When the mobile device does not have GPSeither, the process can also be performed with two virtual objects or avirtual object and the indication of the current location. Furthermore,it is also possible to indicate to the user, as exemplified in FIG. 7A,the “Field of view” (cp. indicator 81 of image section) of the lastimage, and for correction, the user can interactively move the “Field ofview” in the map and reorient the same. Here, the aperture angle of the“Field of view” can be shown in accordance with the intrinsic cameraparameters.

According to this embodiment, the method includes in particular thefollowing steps: providing a map view (cp. map view 80) on the displayof the mobile device and providing a choice for the user to select aviewing direction in taking the image. It is possible in this way toselect in the map the viewing direction in which the user looks with thecamera at the particular moment.

According to another embodiment of the invention, the method comprisesthe additional steps: placing the virtual object in the image of thereal environment and in a map view provided on a display of the mobiledevice, and determining an orientation of the image from a determinedposition of the image and the position of the virtual object in the mapview provided. It is thus possible that virtual objects are placed onthe map and moreover in the perspective image of the real environment,which permits conclusions to be made on an orientation of the user.

In order to allow also other users to view and edit an image of a realenvironment that is augmented with virtual objects, from a distance (forexample, on a client that communicates with the server, e.g. via theInternet), it is provided in an embodiment of the invention that themethod comprises the following further steps:

There is provided at least one image of the real environment togetherwith its pose data on the database of the server. Thereafter, access ismade to the image of the real environment on the server and the image istransmitted to a client device for displaying the image on the clientdevice. The user manipulates the virtual object or adds another virtualobject by corresponding positioning in the image of the real environmentshown on the client device. The manipulated virtual object, togetherwith its modified pose data according to the positioning in the imageshown on the client device, or the further virtual object together withits (new) pose data according to the positioning in the image shown onthe client device, on the database of the server, with the modified posedata or new pose data each permitting a conclusion as to the globalposition and orientation of the manipulated or further virtual object inthe image displayed on the client device. Thus, with a “remote access”on a client device, the AR scene in the image can be modified oraugmented with additional virtual information and be written back to theserver. Due to the newly stored global position of the manipulated ornew virtual information, this position in turn can be retrieved by otherusers via access to the server and can be viewed in an AR scenerycorresponding to the global position.

On the basis of this, the method in still another embodiment comprisesthe following additional steps: accessing the image of the realenvironment on the server and transmitting it to a second client devicefor viewing the image on the second client device and accessing virtualobjects provided on the server, with the view of the image on the secondclient device displaying those virtual objects whose global position iswithin the real environment that is shown in the view of the image onthe second client device. In this way, a viewer can observe, on anotherclient device, a scenery in which those virtual objects are displayedthat were already positioned earlier by other users at a correspondinglocation (i.e. the global position of which is within the realenvironment shown in the view of the image on that client device). Inother words, the viewer sees from his viewing angle those virtualobjects that were already previously placed by other users in thevisible field of view.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed herein as thebest mode contemplated for carrying out this invention.

What is claimed is:
 1. A method for representing image information in aview of a real environment, comprising the steps of: 1a) taking a firstplurality of images of a real environment by means of at least one firstmobile device; 1b) storing the first plurality of images in at least onedatabase; 1c) taking a second image of the real environment by means ofa second mobile device; 1d) accessing the first plurality of imagesstored in the at least one database; 1e) matching the first plurality ofimages against the first plurality of images wherein said matchingcomprises performing bundle adjustment; 1f) determining, for eachrespective image of the first plurality of images, first pose datapermitting a conclusion to be made as to a position and an orientationwith respect to a reference coordinate system in which the respectiveimage was taken according to a result of said matching; 1 g) comparingthe second image with at least one of the first plurality of images; 1h)determining, for at least one presentation image among the firstplurality of images, an overlay position in the second image accordingto a result of said matching and the first pose data associated with theat least one presentation image; and 1i) displaying the at least onepresentation image overlaid at the determine overlay position in thesecond image on a display device.
 2. The method of claim 1, comprisingthe further steps of: providing initial values for the first pose dataassociated with at least one of the first plurality of images; andwherein, in the step 1e), said bundle adjustment is performed withconsideration of the at least one first pose data.
 3. The method ofclaim 1, comprising the further steps of: determining second pose datapermitting a conclusion to be made as to a position and an orientationwith respect to the reference coordinate system in which the secondimage was taken according to a result of said comparing.
 4. The methodof claim 1, comprising the further steps of: providing second pose datapermitting a conclusion to be made as to a position and an orientationwith respect to the reference coordinate system in which the secondimage was taken; and wherein, in the step 1g), said comparing isperformed with consideration of the second pose data and the second posedata is modified according to a result of said comparing.
 5. The methodof claim 4, wherein the overlay position is determined according to themodified second pose data.
 6. The method of claim 1, wherein at leastone of the steps 1d), 1e), 1f), 1g), 1h) is executed in the secondmobile device or in at least one server.
 7. The method of claim 1,comprising the further steps of: providing a reference database withreference views of a real environment together with pose data permittinga conclusion to be made as to a position and an orientation with respectto the reference global coordinate system in which the respectivereference view was taken by a camera; comparing at least one real objectthat is shown in the second image with at least part of a real objectthat is contained in at least one of the reference views, and matchingof the second pose data of the image with the pose data of the at leastone reference view; and modifying at least part of the second pose dataon the basis of at least part of the pose data of the at least onereference view as a result of said matching.
 8. The method of claim 1,wherein said matching in the step 1e) comprises matching image featuresof each of the first plurality of images with corresponding features ofother images of the first plurality of images; and said comparing in thestep 1g) comprises matching image features of the at least one of thefirst plurality of images with corresponding features of the secondimage.
 9. The method of claim 1, wherein the second mobile devicecomprises, or is connected to, the display device.
 10. The method ofclaim 1, wherein the reference coordinate system is a geographic globalcoordinate system or a coordinate system associated with a real objectin the real environment.
 11. The method of claim 1, wherein the at leastone first mobile device and the second mobile device are the same clientdevice, and wherein the at least one database comprises, or is connectedto, the client device or at least one server.
 12. The method of claim 1,wherein the first mobile device and the second mobile device aredifferent client devices, and the at least one database comprises or isconnected to at least one server.
 13. A method for representing virtualinformation in a view of a real environment, comprising the steps of:13a) taking at least one first image of a real environment by means ofat least one first mobile device and providing first pose datapermitting a conclusion to be made as to a position and an orientationwith respect to a reference coordinate system where the at least onefirst image was taken; 13b) adding at least one virtual object bycorresponding positioning in the at least one first image; 13c)providing second pose data in accordance with the positioning of the atleast one virtual object in the at least one first image, wherein thesecond pose data permits a conclusion to be made as to a position and anorientation of the at least one virtual object with respect to thereference coordinate system; 13d) storing the at least one virtualobject, the at least one first image, the first pose data and the secondpose data in at least one database; 13e) taking a second image of thereal environment by a second mobile device; 13f) accessing the at leastone virtual object, the at least one first image, the first pose dataand the second pose data stored in the at least one database; 13g)comparing at least one real object that is shown in the at least onefirst image with at least part of a real object that is contained in thesecond image; 13h) determining third pose data according to a result ofcomparison, wherein the third pose data permits a conclusion to be madeas to a position and an orientation with respect to the referencecoordinate system where the second image was taken; and 13i) displayingthe at least one virtual object superimposed with the second image on adisplay device on the basis of the second pose data and the third posedata.
 14. The method of claim 13, wherein the second mobile devicecomprises, or is connected to, the display device.
 15. The method ofclaim 13, wherein the reference coordinate system is a geographic globalcoordinate system or a coordinate system associated with a real objectin the real environment.
 16. The method of claim 13, wherein the atleast one first mobile device and the second mobile device are the sameclient device, and wherein the at least one database comprises, or isconnected to, the client device or at least one server.
 17. The methodof claim 13, wherein the first mobile device and the second mobiledevice are different client devices, and the at least one databasecomprises or is connected to at least one server.
 18. The method ofclaim 13, wherein at least one of the steps 13f), 13g), and 13h) isexecuted in the second mobile device or in at least one server.
 19. Themethod of claim 13, wherein said comparing in the step 13g) comprisesmatching image features of the at least one first image withcorresponding features of the second image.
 20. A method forrepresenting virtual information in a view of a real environment,comprising the steps of: 20a) providing at least one first view of areal environment by means of first data glasses together with first posedata permitting a conclusion to be made as to a position and anorientation with respect to a reference coordinate system where thefirst data glasses are positioned; 20b) providing at least one firstimage of the real environment taken by a camera connected to the firstdata glasses; 20c) adding at least one virtual object by correspondingpositioning in the at least one first view of the real environment; 20d)providing second pose data in accordance with the positioning of the atleast one virtual object in the at least one first view of the realenvironment, wherein the second pose data permits a conclusion to bemade as to a position and an orientation of the at least one virtualobject with respect to the reference coordinate system; 20e) storing theat least one virtual object, the at least one first image, the firstpose data, and the second pose data in at least one database; 20f)providing at least one second view of a real environment by means ofsecond data glasses; 20g) providing at least one second image of thereal environment taken by a camera connected to the second data glasses;20h) accessing the at least one virtual object, the at least one firstimage, the first pose data, and the second pose data stored in the atleast one database; 20i) comparing at least one real object that isshown in the at least one first image with at least part of a realobject that is contained in the at least one second image; 20j)determining third pose data according to a result of comparison, whereinthe third pose data permits a conclusion to be made as to a position andan orientation with respect to the reference coordinate system where thesecond data glasses are positioned; and 20k) displaying the at least onevirtual object superimposed with the at least one second view on thebasis of the second pose data and the third pose data.
 21. The method ofclaim 20, wherein the first pose data is determined according to the atleast one first image.
 22. The method of claim 20, wherein the firstdata glasses and the second data glasses are the same client device ordifferent client devices.